Characterizing Physiological and Proteomic Analysis of the Action of H2S to Mitigate Drought Stress in Young Seedling of Wheat

Hydrogen sulfide (H2S) is a gaseous signaling molecule that has been shown to improve drought resistance in plants. In this study, comparative physiological and proteomic analyses were performed to investigate the underlying mechanism by which H2S alleviates drought stress in wheat seedlings. Pretreatment with sodium hydrosulfide (NaHS), an H2S donor, significantly increased height and decreased lipid peroxidation levels in wheat seedlings under drought stress. The antioxidant levels (ascorbate and reduced glutathione), and the contents of starch and soluble sugars were all increased in plants pretreated with NaHS. Using the iTRAQ (isobaric tags for relative and absolute quantitation) technique, 120 proteins were found to be significantly regulated by NaHS under drought stress (57 increased and 63 decreased) compared with drought treatment without NaHS. Functional annotation showed that these proteins are mainly related to carbohydrate metabolism, photosynthesis, signal transduction, protein synthesis, stress, and secondary metabolism. Nine proteins were selected to examine the transcriptional levels of their corresponding genes, and most of them displayed expression patterns similar to the proteomic profiles. These results show that H2S can alleviate drought stress in wheat seedlings by regulating multiple biochemical pathways and that energy and carbon metabolism, signal transduction, antioxidant capacity, and protein synthesis may play important roles in the regulation of drought stress in plants.